Concerns raised about cancers connected to Humira, Remicade and Enbrel

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WASHINGTON — Federal regulators are investigating whether a group of best-selling arthritis drugs made by Abbott Laboratories, Schering-Plough Corp. and other companies heighten the risk of cancer in youngsters.

Rates of women who are opting for preventive mastectomies, such as Angeline Jolie, have increased by an estimated 50 percent in recent years, experts say. But many doctors are puzzled because the operation doesn't carry a 100 percent guarantee, it's major surgery -- and women have other options, from a once-a-day pill to careful monitoring.

The Food and Drug Administration said Wednesday it has received 30 reports of children and young adults developing cancer while taking the drugs over the last 10 years. Roughly half the cases were lymphomas, a type of immune-system cancer. Others reported were leukemia, melanoma and cancers of various organs.

The drugs under review include Abbott Labs' Humira, Schering-Plough's Remicade, and Enbrel, which is marketed by Amgen Inc. and Wyeth. They are prescribed to children with arthritis to block a chemical that causes inflammation. The drugs also are used to treat children with the intestinal disorder Crohn's disease.

The products, known as tumor necrosis factor blockers, are key revenue drivers for the companies. Abbott's Humira was the company's best-selling product last year with over $3 billion in sales. Remicade also topped Schering-Plough's portfolio with sales of $1.65 billion.

The safety of Humira was reviewed in February when the FDA first cleared it for use in juvenile arthritis, Abbott said in a statement. The company has not recorded any instances of lymphoma in children.

Representatives from the other companies did not immediately return calls for comment Wednesday morning.

The FDA said the drugs' labeling already warns of a potential association with cancer, but the agency's investigation will focus on risks to younger patients.

The statement posted to the FDA's Web site said it will take long-term studies to definitively assess the drugs' safety risks since cancers take years to develop.

Belgian drug maker UBC is conducting a long-term study of risks, including cancer, with its drug Cimizia, which is part of the medication class. But the FDA said that study won't be complete until 2019.

The agency has asked drug makers to provide all information about children who developed cancer while taking the medications. Regulators will report the findings of their review by November.

Doctors should consider the risks of cancer when considering prescribing the drugs for youngsters, the FDA said.